1. Field of the Invention
The present application relates to a display device. More particularly, the present application relates to a transparent display device adapted to enhance display efficiency.
2. Background of the Related Art
In general, liquid crystal display (LCD) devices, plasma display panels (PDPs) and organic light emitting display (OLED) device have features of thinness, light weight, low power consumption and low driving voltage compared to cathode ray tube (CRT) displays. As such, the LCD devices, the PDPs and the OLED display devices are being applied to a variety of appliances.
Recently, transparent display devices are intensively being developed as next generation display devices. The transparent display device not only performs a general display function but also selectively displays rear scenes by transmitting light.
A transparent OLED (organic light emitting display) device among the transparent display devices cannot realize black. To address this matter, the transparent OLED device employs a variable light shield plate which is attached to the rear surface of an OLED panel. However, misalignment and moire problems can be generated because the variable light shield plate must be attached to the OLED panel. Moreover, the transparent OLED device must be thicker.